555 timer icProteus Simulation Based Projects

Schematic Circuit Diagram Variable frequency PWM Using 555-Timer proteus simulation

By including a variable resistor in series with the capacitor in the above circuit, frequency can be varied along with the duty ratio. As this resistor is involved in both charging and discharging periods, this does not affect the duty ratio.

Variable frequency PWM Using 555-Timer

Schematic Circuit Diagram Variable frequency PWM Using 555-Timer proteus simulation

This circuit can be used for speed control of motors, brightness control of lights etc., even if the specific frequency for proper operation is not known as in the case of dc fans or dc motors. It can be set by trial and error. The minimum time period of the waveform depends on the duty cycle potentiometer and maximum time period depends on the frequency potentiometer. Variable resistors should not be in their extreme positions or use fixed resistors in addition to a potentiometer to avoid this.

Simulation – Waveforms of Variable frequency PWM

Tags

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button
Close
Close
Read previous post:
Schematic Circuit Diagram Constant frequency PWM Using 555-Timer proteus simulation

Constant frequency PWM Using 555-Timer With the basic astable circuit, the duty ratio cannot be controlled without affecting the frequency....

Close